The present invention relates to fluorine-containing quaternary ammonium compounds and their production. More particularly, it relates to fluorine-containing quaternary ammonium compounds which are effective in reducing the surface tension of water as well as the interfacial tension between water and oil, and their production.
In general, fluorine-containing compounds can reduce the surface tension of water and are useful as evaporation-preventing agents, leveling agents, etc. On the other hand, there are considerable demands for additives to aqueous foam fire-extinguishing agents. Since such fire-extinguishing agents are necessitated to spread quickly over an oil surface to form an aqueous film, the said additives are required to have not only a capability of reducing the surface tension but also a capability of reducing the interfacial tension between water and oil. Namely, the spreading coefficient (S) has the following relationship with the surface tension of oil (.gamma..sub.o), the surface tension of water (.gamma..sub.w) and the interfacial tension between water and oil (.gamma..sub.wo): S=.gamma..sub.o -(.gamma..sub.w +.gamma..sub.wo), and water can spread over the oil surface only when S is positive. Unfortunately, however, the fluorine-containing group in conventional fluorine-containing compounds has only a low affinity to oil so that the satisfactory orientation at the interface between water and oil can not be attained. Thus, conventional fluorine-containing compounds can not sufficiently reduce the interfacial tension between water and oil. In order to supplement such insufficiency, the simultaneous use of a hydrocarbon compound surfactant is thus necessary.
Japanese Patent Publication (examined) No. 21133/1974 discloses amines having a fluoroalkyl group and their salts with organic or inorganic acids. While they are quite effective in reducing the surface tension of water, their capability of reducing the interfacial tension between water and oil is still not satisfactory. For using them practically as additives to aqueous foam fire-extinguishing agents, their activity for reducing the interfacial tension between water and oil must be enhanced by any appropriate means.